Well, it depends on the problem. If your stream is loaded with pathogens and nutrients, it could be your cows. If your stream is loaded with mud it could be your cows too, if they are allowed access to the stream. But TDEC cannot regulate farms. Farms are exempt from the CWA as well as the TNWQCA, so even if your cows are the problem, TDEC can't really do anything about it.
 
Currently, there is a move afoot to scare farmers that TDEC is gonna getcha! Do not believe that for one moment. TDEC has neither the will nor the inclination to get anyone, much less farmers. TDEC is complaint driven. They do not look for opportunities to enforce the TN WQCA against anyone, much less the farming community. This is simply a scare perpetrated by the Farm Bureau Federation to keep farmers in the dark about how the CWA and the TNWQCA really work. These laws are in place to protect water for farming, recreation, industry and domestic (homes) use. Farmers don't want to farm with dirty water anymore than they want to drink it.
 
Relaxing water quality rules, as the Farm Bureau Federation of Tennessee is working hard to do in the state legislature, actually benefits developers, not farmers. Development is one of the biggest threats to family farms in Tennessee. When water quality laws are relaxed, farms downstream of developments get hit the hardest.